Added files
Functional prototype
Apparently working prototype with tests
Symmetrical mode.

- Added a symmetrical misfit mode. This runs the lam2 misfit process with the two
  operators in both directions, and takes the average misfit of the two.
Initiated a splitting misfit example.
First stab at effective splitting using wavelet

Use [fast tlag] = MS_effective_splitting_N(0.1, ...
 55.0, [55.0 10.0], [1.0 1.0], 'mode', 'gaussianwavelet')
to do effective splitting calcualtion using this new
method.
Add tests, unwind output

Make the output consistent with the S&S method. Add tests
following some of those from S&S. Note that in three cases
(tests commented out) the result is a few degrees different.
Shows up more for longer periods. Is this close to a faliure
mode for S&S or is something wrong with the wavelets?
Remove some code duplication from new functions

And tidy up the comments.
Move splitting measurment into seperate function
Teach the split_model about new eff split mode

Add optional arguments:

* split_model("mode", eff_split_mode) where eff_split_mode is a
  string passed into the mode argument of MS_effective_splitting_N.
  Note that setting this to 'GaussianWavelet' results in a much
  longer execution time for the example and the remaining options
  can be used to limit this.
* split_model("min_azi", min_azi) the minimum azimuth considered for
  the calculation (default 0 degrees).
* split_model("max_azi", max_azi) the maximum azimuth considered for
  the calculation (default 360 degrees).
* split_model("del_azi", del_azi) the azimuthal spacing used for the
  calculation (default 1 degree).
Seperae and tidy up trace plotting functions

This merges the final common functions from
MS_effective_splitting_N and MS_splitting_misfit
and provides a framework for plotting 'traces'
used for some splitting calculations.
Merge branch 'splitting' of ssh://majorite/geophysics/walker/git-repos/msat into splitting
Added optional weight output to split_misfit. Still need to implement something
useful for this.
Added a basic demo for the splitting misfit calculation. This is still a work
in progress.
* Improvements to splitting misfit calculations.
- Added 'split intensity' misfit mode, and documented.
- Removed the option to return a weight (this wasn't used by any
  of the codes.)
Minor comment fixes
* Added a code to demonstrate the different misfit functions implemented
  in MS_split_misfit.m.
Make MS_measure_trace_splitting stricter

And add options to chance this and plot the
error surface. Using this version we get
reasonable results for the splitting_example
using the wavelet approach. Include
two pictures.
Trap unknown arguments

Or we loop forever.
* Improvements to splitting misfit demo.

- Added several source polarisations to demonstrate the effect of
  this on misfit functions.

- Tidied up the code.